EP2507548B1 - Retrofit led lamp - Google Patents

Description

The invention deals with an LED lamp. It focuses in particular on so-called retrofit LED lamps, which are designed as a replacement for halogen lamps or incandescent lamps.

For lighting LED lamps are used more often. These are characterized by their high light efficiency and longevity. Furthermore, they can be used very flexibly due to their extremely small dimensions. LEDs are usually manufactured as LED modules. It is to think of LED modules, consisting of at least one blue LED, which generates white light arranged by arranged on the LED wavelength conversion means. By means of RGB LED modules, it is possible to produce any desired colors, wherein a setting and a dimming via a PWM control of the individual color channels can be realized.

Particular preference is given to using LED lamps in the form of so-called retrofit LED lamps. Here, the LED lamp with regard to their mechanical and electrical connections to replace existing bulbs (light bulb, halogen, ...) is formed. In order to adapt the supply current, the retrofit LED lamp also usually has its own driver circuit which, starting from, for example, adapts the supply current to the operating conditions of the LEDs from a mains voltage supplied via the base. Thus, the retrofit LED bulbs like conventional bulbs in ordinary lamp sockets are screwed and operated by means of the supplied mains power.

However, LEDs pose the problem that the LED chips and / or their driver circuitry generate heat during operation, including but not limited to: can lead to unwanted changes in the emitted color spectrum and to a shorter lifetime. Accordingly, it is important to provide effective cooling of the LED. Cooling is also advantageous for reliable operation of the driver circuit of the LED. The use of LEDs in retrofit LED lamps, however, the space is severely limited, so that no large and thus powerful cooling can be used. Therefore, it is crucial to use a particularly efficient cooling that can be used in a small space while still dissipate as much heat.

In the pamphlets US 2009/0244899 A1 . DE 20 2005 006 332 U1 . DE 10 2007 037 190 A1 and DE 20 2008 013 667 U1 various heatsink arrangements are shown.

The invention is therefore based on the object to provide an efficient and space-saving heat sink assembly for an LED lamp, in particular for a retrofit LED lamp.

• einen Trägereinsatz bestehend aus einer Trägerplatte mit einstückig angesetztem Kragen,
• wobei die Trägerplatte, direkt oder indirekt, in wärmeleitfähigem Kontakt das LED-Modul trägt,
• wobei an dem Kragen des Trägereinsatzes in Richtung des Sockels zur Wärmeabfuhr in flächigem Kontakt eine wärmeleitfähige Unterschale angebracht ist

The object is achieved by the features of the independent claims. The dependent claims represent advantageous developments of the invention. An aspect of the invention relates to a heat sink arrangement for dissipating the heat arising during operation on a light source, in particular on an LED module, and / or on a driver circuit for the light source, comprising:

• a carrier insert consisting of a carrier plate with an integrally attached collar,
• wherein the carrier plate, directly or indirectly, carries the LED module in thermally conductive contact,
• wherein on the collar of the carrier insert in the direction of the base for heat dissipation in surface contact, a thermally conductive lower shell is attached

The carrier insert may be made of a high thermally conductive material, preferably having at least 10W / mK thermal conductivity.

The carrier insert may be formed of metal, plastic and / or ceramic.

The thermally conductive lower shell may consist of one or more layers of a plastic material, metal and / or ceramic.

The thermal conductivity of the plastic material, for example a polymer, or the ceramic is preferably greater than 1 watt / meter Kelvin, preferably greater than 2 watt / meter Kelvin.

The lower shell may consist of an inner and an outer layer, wherein the inner layer makes a full-surface contact with at least a part of the outer layer.

The outer layer of the lower shell may be at least partially applied as a coating on the inner layer of the lower shell member.

The inner layer of the lower shell may be made of metal, in particular of aluminum.

The outer layer of the lower shell may consist of an electrically insulating material.

The inner layer and the outer layer of the lower shell may be formed as separate parts.

The annular region in which the lower shell overlaps the collar of the carrier insert may have a side height of preferably more than 2 mm, more preferably greater than 3 mm.

The collar of the carrier insert may be received in a recess in the inside of the lower shell, so that the inner surface of the collar of the carrier insert is flush with the inner side of the region of the lower shell with greater wall thickness.

• wenigstens eine Kühlkörper-Anordnung nach einem der vorherigen Ansprüche,
• ein LED-Modul mit einem oder mehreren LED-Chips, eine Treiberschaltung zur Stromversorgung des LED-Moduls, sowie einen Sockel zum mechanischen wie elektrischem Kontakt mit einer Glühbirnenfassung, und
• eine transparent Oberschale, die in Lichtaustrahlrichtung des LED-Chips an dem Kragen des Trägereinsatzes und/oder an der Unterschale angebracht ist.

Another aspect of the invention relates to a retrofit LED lamp, comprising:

• at least one heat sink arrangement according to one of the preceding claims,
• a LED module with one or more LED chips, a driver circuit for powering the LED module, and a socket for mechanical and electrical contact with a bulb socket, and
• a transparent upper shell, which is mounted in the light emitting direction of the LED chip on the collar of the carrier insert and / or on the lower shell.

The lower shell and the upper shell may form a LED lamp housing enclosing the LED module and the carrier insert.

The lower shell and the collar of the carrier insert may form a hollow body in which at least a part of the driver circuit for the LED module is arranged.

The outer layer of the lower shell and the upper shell may consist of an electrically insulating material.

The lower shell may surround the driver circuit at a distance.

The outer layer of the lower shell and the upper shell may have a thickness of at least 100 .mu.m, preferably at least 200 .mu.m, more preferably at least 500 .mu.m, and most preferably at least 1000 .mu.m.

The outer layer of the lower shell and the upper shell may consist of an electrically insulating material.

Between the driver circuit and the inner layer of the lower shell, an electrical insulation may be provided.

The outer layer of the lower shell may be at least partially applied as a coating on the inner layer of the lower shell member.

The outer layer of the lower shell may have a corrugated shape for increasing the surface, at least in the region of its lower part.

The lamp base can be connected to the lower part of the outer and / or the inner layer surface, so that a high heat output from the inner and / or the outer layer is ensured.

The LED module can have at least one RGB LED module and / or at least one phosphor-converted monochromatic LED with at least one monochromatic LED.

The driver circuit can have an AC-DC converter and / or a DC-DC converter, in particular with a PWM-operated switch.

The LED lamp may include a lamp cap for mechanically and electrically contacting the LED lamp with a lamp socket, wherein the lamp cap is an E14, E17 or E27 screw base or a G4, G5 or G6 pin header or a BA9 or BA15 bayonet socket ,

The lamp base can be connected to the lower part of the outer and / or the inner layer of the lower shell surface, so that a high heat output from the inner and / or the outer layer is ensured.

Further advantages, characteristics and features of the invention will now be explained with reference to the figures of the accompanying drawings.

Fig. 1a

eine erfindungsgemäße Ausführungsform einer Retrofit LED-Lampe in einer Explosionsansicht,

Fig. 1b

die Ausführungsform von Fig.1a in zusammengebauter Weise, und

Fig.2

eine weitere erfindungsgemäße Ausführungsform einer Retrofit LED-Lampe mit einteiliger Unterschale.

Show it:

Fig. 1a

an embodiment of a retrofit LED lamp according to the invention in an exploded view,

Fig. 1b

the embodiment of 1a in an assembled way, and

Fig.2

a further embodiment of a retrofit LED lamp with one-piece lower shell according to the invention.

Fig. 1a and 1b show an embodiment of the invention an LED lamp 1 with an LED module 7. This is a retrofit LED lamp 1 for use in a conventional lamp socket. For this purpose, the lamp 1 has a conventional socket 2, for example with an E14, E17 or E27 screw thread. Alternatively, a socket is conceivable that is designed for a low-voltage connection, such as a G4, G5 or G6 pin header. Also conceivable is a BA9 or BA15 bayonet socket.

If the retrofit LED lamp 1 is powered by a corresponding lamp socket with mains AC voltage or low voltage, a current adjustment is required for correct operation of the LED module 7. For this purpose, a driver circuit 5 is provided. This can have any conceivable drive circuit for this application, as is known from the prior art. For example, think of an AC-DC converter for rectifying an AC line voltage. Advantageously, this can be followed by a DC-DC converter or other converter, which reduces the voltage or the current or the power. In this case, a switch can be used, which is switched by means of pulse width modulation (PWM). It is also to think of a downstream current limiting circuit, for example by means of a transistor circuit.

The LED module 7 can have one or more LEDs and / or OLEDs. In particular, phosphor-converted monochromatic eg blue LEDs, RGB LED modules or any combinations thereof can be used. The phosphor-converted LEDs are, in particular, at least one blue LED in which a part of the emitted blue light is converted into yellow or greenish yellow light by color conversion means such as phosphor. The application of phosphor-converted green and / or greenish white LEDs is also conceivable. Preferably, in addition one or more red LEDs (or other monochromatic LEDs) are used, which leads to a higher color rendering value Lead CRI and provide for a warmer light. The red LEDs can be arranged separately from the phosphor-converted blue LEDs, or they can be located next to them, so that also a part of their emitted red light is phosphor converted.

The LED module can be realized as a COB ("chip-on-board") module.

According to the invention, the LED module 7 now sits on a carrier insert 6, which is part of a heat sink arrangement. Thus, the LED module and the carrier insert 6 are connected flat. In this case, the carrier insert 6 in the region in which the LED module rests as flat as possible, so that the carrier insert 6 and the LED module 7 have the highest possible contact surface, ie that they are connected over the entire surface. The carrier insert 6 may consist of an upper part 6 and a lower part 4. Thus, the carrier insert 6 may at least partially enclose the driver circuit 5. The lower part 4 advantageously has an opening on the underside, whereby the driver circuit 5 can protrude or through which a conductor can protrude, which produces an electrical contact with power supply. The upper part 6 also has a bulged outward shape, so that there is sufficient space on the inside for the driver circuit. On its outside, preferably in the middle of the bulge, it has a flat area on which the LED module 7 is mounted. The upper part 6 may thus have an approximately hemispherical shape, which is flattened on its upper side. The upper and lower parts 6 and 4 are connected as flat as possible and thus have a heat transfer between the parts and a strong mechanical fixation. For this purpose, a bayonet closure, a screw thread or a linear, conical or stepped connection can be used as the connection. It is also conceivable that a part is inserted into the other clip-like. Moreover, by the two-part embodiment of the inner layer, the mounting of the LED module 7 on the tray 6 is easier to perform because the upper side can be used separately from the lower side, and the driver circuit 5 can be more easily inserted. The upper side 6 may additionally have optical means in the region of the LED module, such as a cavity in which the LED module is mounted. However, it is advantageous if the generated light can emerge at a large angle.

The carrier insert 6 may consist of a good thermal conductivity material such as metal, for example. Aluminum. The use of plastic, ceramic or any combination thereof are also conceivable.

The carrier insert 6 can overlap on the largest possible surface with the lower part of the housing (or lower shell). The carrier insert 6 is at least at its collar 10 in a length L (in the lateral view of FIG. 1a, 1b ) of at least preferably 2mm with at least the inner layer of the lower part in surface contact.

The heat sink assembly further includes an outer layer surrounding the support insert, wherein the outer layer has the largest possible surface area. This layer also consists of an upper part 8 and a lower part 3. These are preferably connectable via a thread or by gluing, thus ensuring a high mechanical fixation and a high heat transfer through a large common surface between the parts. The outer view is preferably made of a non-conductive material such as plastic, or at least of a low-conductivity material having an insulating property. In addition, it has a lower thermal conductivity than the inner layer.

This results in the advantageous effect that heat from the heat source, ie from the LED module and also from the driver circuit by means of the inner layer is quickly removed and then absorbed by the outer layer. For this purpose, the inner and the outer layer are at least partially flush with each other. This is in the embodiment of Fig. 1b in the two subparts 4 and 3 of the case. Thus, both layers have the largest possible abutting surface, and thus the largest possible heat transfer between the two layers is guaranteed. For this purpose, the two lower parts 4 and 3 are also shaped so that they rest against each other as possible without an air gap. You can, for example, have a conical shape with low tolerances. It is also conceivable that to increase the adjacent Surfaces of the outer and inner layers, the layers have a corresponding, interlocking structure, such as ribs or waves.

Between the upper parts of the carrier insert 6 and the outer layer 8 is a space in which the LED module is located. This space may include optical means such as a lens. Furthermore, it is possible that this space is at least partially filled, for example, with a transparent material, so that also heat dissipation between the two tops can be done.

The lower part of the outer layer is connected to the lamp cap 2 so that both parts have a large common surface. Thus, a high heat transfer between the outer layer and the lamp cap is ensured.

The outer layer is also at least partially, in particular in the region of the upper part 8, translucent or transparent, so that the light generated by the LED module 7 shines through. The upper part 8 can also have optical properties such as a lens, diffuser particles or the like.

The outer layer has a thickness of at least 100 μm, preferably of at least 200 μm and more preferably of at least 500 μm, but more preferably of at least 1000 μm.

There may be a gap between the carrier insert and the driver circuit. This can be filled with air. It is also conceivable that he be filled with a potting compound. In this case, the potting compound can also represent a connection of all parts of the cooling arrangement, the lamp cap 2, as well as the driver circuit. Thus, a mechanical fixation and a heat transfer between the parts is favored.

Contact between the liner and the outer layer may also be made by applying the outer layer over the metallic liner by a molding process. A mechanical fixation can be made via standard methods such as ribs or cavities in metal use. The outer layer and the metallic carrier insert may also be connected by means of a bonding agent such as adhesive, grease, cement or an elastomer.

The carrier insert may have at least partially an additional, third layer on its inner surface. This has insulating properties. Thus, the driver circuit can be further protected against short circuits. It is conceivable that this insulating layer has a recess in the region below the LED module, so that via the inner, conductive layer, an electrical connection between the driver circuit and the LED module can be made. However, it is also conceivable that the third layer is formed continuously and inner layer and the third layer in the region of the LED module are pierced to make contact with conductors.

In the previous embodiment, it is therefore assumed that the carrier insert consists of two composite parts with high thermal conductivity, e.g. Metal parts 4, 6, wherein the upper part is in thermal contact with the LED board. A second lower part 3 forms the back of a candle-shaped retrofit LED lamp and extends to the base of the LED lamp. Outwardly, the back metal part is coated (overmolded) with a thin plastic material of, for example, 0.5 mm, which is electrically insulated.

In contrast, shows Fig. 2 a further embodiment of an LED lamp according to the invention, in which the carrier insert 6 consists of a good thermal conductivity material such as metal, ceramic, plastic, which preferably has at least 10W / mK thermal conductivity. It is, for example, a metallic support insert 6 consisting of a support plate 11 with an integrally attached collar 10, wherein the support plate 11 carries again in thermally conductive contact the LED module.

The back part, ie the lower shell is in contrast to the multi-part construction of FIG. 1 formed in one piece and may, for example, from a thermally conductive plastic material, such as a polymer, or consist of a ceramic. Materials having at least preferably 1W / mK, more preferably at least 2W / mK, thermal conductivity can be used in this embodiment.

On the collar 10 of the carrier insert 6 is a transparent upper shell 8 and in the direction of the base for heat dissipation in planar contact the thermally conductive preferably one-piece lower shell 9 is attached, which together a LED module and the support insert 6 enclosing housing the LED lamp form.

In this case, the wall thickness of the lower shell in the region in which it is connected to the heat sink 6, d. H. the collar area, overlapped and in contact with the entire surface, for example, only 2mm. In the area of the lower shell in which there is no overlap, the wall thickness is greater, for example in a range of 3 to 5 mm.

The largest part of the heat transfer to the outside is thus in the region of the collar of the carrier insert by the full-surface contact with the lower shell, which consists for example of a thermally conductive plastic material done.

Preferably, the collar of the carrier insert is received in a recess in the inside of the thermally conductive plastic material, so that the inner surface the support insert flush with the inside of the region of the heat-conductive plastic material with greater wall thickness.

Since the lower shell 9 made of plastic material and thus also the inner side naturally has electrically insulating properties, the driver circuit can be protected against short-circuits without further structural changes.

The further features of this embodiment do not differ from the features of the preceding embodiment and will therefore not be further described.

Claims (21)

1. A cooling body assembly for dissipating the heat produced during the operation on a light source, in particular on an LED module (7), and/or on a driver circuit (5) for the light source, having:

   A carrier insert (6) consisting of a carrier plate (11) with an integrally attached collar (10), wherein the carrier plate carries the LED module in thermally-conductive contact, and

   wherein a thermally-conductive lower shell (4) is arranged in the direction of the base for dissipating heat in flat contact, wherein the lower shell consists of an inner (4) and outer (3) layer, wherein the inner layer establishes a full-area contact with at least one part of the outer layer,

   characterized in that

   the inner layer of the lower shell consists of metal, in particular of aluminum, and the outer layer of the lower shell consists of an electrically insulating material, and

   the outer layer of the lower shell is applied at least partially as a coating to the inner layer of the lower shell.
2. A cooling body assembly according to Claim 1,
   wherein the carrier insert is made from a good thermally-conductive material, which preferably has at least 1OW/mK thermal conductivity.
3. A cooling body assembly according to Claim 1 or 2,
   wherein the carrier insert is formed from metal, plastic and/or ceramic.
4. A cooling body assembly according to any one of the preceding claims,
   wherein the thermally-conductive lower shell consists of at least one layer of a plastic material, such as, for example, a polymer, a metal or a ceramic.
5. A cooling body assembly according to Claim 4, wherein the thermal conductivity of the plastic material or ceramic is greater than 1 watt/meter kelvin, preferably greater than 2 watts/meter kelvin.
6. A cooling body assembly according to any one of the preceding claims,
   wherein the annular region, in which the lower shell overlaps with the collar of the carrier insert, is a lateral height of preferably greater than 2 mm, more preferably greater than 3 mm.
7. A cooling body assembly according to any one of the preceding claims, wherein the collar of the carrier insert is accommodated in a set-back portion in the inside of the lower shell, so that the inner surface of the collar of the carrier insert is flush with the inside of the region of the lower shell with greater wall thickness.
8. A retrofit LED-lamp having at least one cooling body assembly according to any one of the preceding claims,
   an LED module with one or several LED chips, a driver circuit for the power supply of the LED module, as well as a base for the mechanical and electrical contact with a light bulb socket,
   further having
   a transparent upper shell, which is arranged in the light emission direction of the LED chip on the collar of the carrier insert or on the lower shell.
9. A retrofit LED-lamp according to Claim 8,
   wherein the lower shell and the upper shell form a housing of the LED-lamp surrounding the LED module and the carrier insert.
10. A retrofit LED-lamp according to Claim 8 or 9,
    wherein the lower shell and the collar of the carrier insert forms a hollow body, in which at least one part of the driver circuit is arranged for the LED module.
11. A retrofit LED-lamp according to any one of the preceding Claims 8 to 10, wherein the outer layer of the upper shell and the lower shell consists of an electrically insulating material.
12. A retrofit LED-lamp according to any one of the preceding Claims 8 to 11,
    wherein the lower shell surrounds the driver circuit at a distance.
13. A retrofit LED-lamp according to any one of the preceding Claims 8 to 12,
    wherein the outer layer of the lower shell and the upper shell has a thickness of at least 100 µm, preferably of at least 200 µm, even more preferably of at least 500 µm and most preferably of at least 1000 µm.
14. A retrofit LED-lamp according to any one of the preceding Claims 8 to 13,
    wherein the outer layer of the lower shell and the upper shell consists of an electrically insulating material.
15. A retrofit LED-lamp according to any one of the preceding Claims 8 to 14,
    wherein an electrical insulation is provided between the driver circuit and the inner layer of the lower shell.
16. A retrofit LED-lamp according to any one of the preceding Claims 8 to 15, wherein the outer layer of the lower shell is applied at least partially as a coating to the inner layer of the lower shell element.
17. A retrofit LED-lamp according to any one of the preceding Claims 8 to 16,
    characterized in
    that the lamp base is connected in a planar manner to the lower part of the outer and/or the inner layer, so that a high heat emission is ensured from the inner and/or the outer layer.
18. A retrofit LED-lamp according to any one of the preceding Claims 8 to 17, wherein the ED module has at least one RGB-LED module and/or at least one luminescent substance-converted monochromatic LED with at least one monochromatic LED.
19. A retrofit LED-lamp according to any one of the preceding Claims 8 to 18, wherein the driver circuit has an AC-DC converter and/or a DC-DC converter, in particular with a PWM-operated switch.
20. A retrofit LED-lamp according to any one of the preceding Claims 8 to 19, wherein the LED lamp has a lamp base for the mechanical and electrical contacting of the LED-lamp with a lamp socket, in which the lamp base is a E14, E17 or E27 screw base or a G4, G5 or G6 pin base or a BA9 or BA15 bayonet base.
21. A retrofit LED-lamp according to any one of the preceding Claims 8 to 20, wherein the lamp base is connected in a planar manner to the lower part of the outer and/or the inner layer of the lower shell, so that a high heat emission is ensured from the inner and/or the outer layer.

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